The climate change debate has taken a new turn as a new study found that despite previous claims, greater reliance on natural gas would not help slow down climate change.
Although the burning of natural gas emits far less carbon dioxide than coal, it seems that news of its climate change mitigation benefits may have been exaggerated, as study led by Tom Wigley, a senior research associate at the National Center for Atmospheric Research (NCAR), indicates.
When used, coal produces emission of heat-trapping carbon dioxide, it also generates comparatively large amounts of sulfates and other particles, which despite being detrimental to the environment also cool the planet by blocking incoming sunlight ,producing an "harm reduction" side effect.
However there is also uncertainty over the amount of methane, a powerful greenhouse gas with many times the global warming potential (GWP) of carbon dioxide, leaking from natural gas operations.
The burning of natural gas doesn't generate the same level of particulate shielding effect.
"Whatever the methane leakage rate, you can't get away from the additional warming that will occur initially because, by not burning coal, you're not having the cooling effect of sulfates and other particles," Wigley said.
"This particle effect is a double-edged sword because reducing them is a good thing in terms of lessening air pollution and acid rain. But the paradox is when we clean up these particles, it slows down efforts to reduce global warming," he added.
Results of the study, where computer simulations were used, found that a partial shift from coal to natural gas would slightly accelerate climate change through at least 2050, even if no methane leaked from natural gas operations and until 2140 if there were substantial leaks but passed this date it would begin to slow down the increase in global average temperature "only by a few tenths of a degree."
"Relying more on natural gas would reduce emissions of carbon dioxide, but it would do little to help solve the climate problem," says Wigley.
"It would be many decades before it would slow down global warming at all, and even then it would just be making a difference around the edges," he added.
The study will appear next month in the peer-reviewed journal Climatic Change Letters.